TNP-470和碱性成纤维细胞生长因子在血管内皮细胞增生中的相互作用

目的:检测TNP-470对内皮细胞增生的影响及其与碱性成纤维细胞生长因子的相互作用,并探讨其可能机制。方法:实验于2005-05/2006-10在沈阳医学院完成。采用本室改进的Jaffe法进行人脐静脉内皮细胞原代培养,细胞生长达亚融合状态后,换成无血清培养液使其停止生长。实验分组:依据施加的实验因素不同,将培养的人脐静脉内皮细胞分为4组:对照组(DMEM无血清)、TNP-470组(10-4g/L)、碱性成纤维细胞生长因子组(500μg/L)、碱性成纤维细胞生长因子 TNP-470组。实验评估:采用四甲基偶氮唑盐比色分析测定各组内皮细胞吸光度,流式细胞计数仪检测内皮细胞周期各时相相对细胞数,免疫组织化学SABC法检测内皮细胞中核因子Kappa B p65和ki-67蛋白的表达阳性率。结果:①人脐静脉内皮细胞的生长活性:TNP-470显著抑制内皮细胞增生;碱性成纤维细胞生长因子显著刺激内皮细胞增生,与对照组相比,差异显著(0.119±0.002,0.168±0.004,0.138±0.003,P<0.05)。②内皮细胞周期各时相相对细胞数:TNP-470阻滞内皮细胞进入增殖期,使G0/G1期内皮细胞比例上升,S期 G2/M期比例下降;而碱性成纤维细胞生长因子具有很强的促内皮细胞分裂增殖活性,使G0/G1期内皮细胞比例减少,S期 G2/M期比例增加,与对照组相比,差异显著(P<0.05)。③各组人脐静脉内皮细胞中NF-κB p65蛋白及Ki-67蛋白的表达阳性率:对照组人脐静脉内皮细胞中NF-κB p65蛋白呈棕褐色染色、ki-67极少表达;TNP-470可显著降低碱性成纤维细胞生长因子诱导的内皮细胞核内NF-κB p65蛋白及Ki-67蛋白的表达,与碱性成纤维细胞生长因子组比较,差异显著[NF-κB p65蛋白:(16.200±1.344)%,(68.400±1.204)%;Ki-67蛋白:(1.500±0.813),(65.700±1.113)%,P<0.05]。结论:TNP-470通过细胞周期阻滞作用抑制内皮细胞分裂与增殖;TNP-470抑制成纤维细胞生长因子诱导的内皮细胞增生与其影响内皮细胞中NF-κB的表达有关。     

泰索帝对人甲状腺未分化癌细胞系(TA-K)增殖抑制作用

目的研究泰索帝对甲状腺未分化癌细胞系（TA-K）的增殖抑制作用。方法用MTT法检测不同浓度、不同作用时间泰索帝对人甲状腺未分化癌细胞系（TA-K）的增值情况。结果TA-K在泰索帝作用下细胞增殖受到抑制，当浓度为0．01μg/ml抑制作用最明显，随着作用时间的延长，抑制率增加。结论泰索帝对甲状腺未分化癌细胞有明显的抑制作用。     

Effects of albendazole, fumagillin, and TNP-470 on microsporidial replication in vitro.

Presently, the two most commonly used drugs for treating microsporidiosis in persons with AIDS are albendazole and fumagillin. Albendazole is effective for treating disseminated infections due to Encephalitozoon spp. but is variably effective against Enterocytozoon bieneusi infections. Fumagillin is highly effective when used topically to treat ocular infections with Encephalitozoon hellem or Encephalitozoon intestinalis but is too toxic for systemic use. In this study, the fumagillin analog TNP-470 was assayed for antimicrosporidial activity in vitro. The MICs of TNP-470 at which 50% of isolates were killed (MIC50s) were 0.35 +/- 0.21 and 0.38 +/- 0.11 ng/ml for E. intestinalis and Vittaforma corneae, respectively, and were similar to the MIC50s of fumagillin for these organisms, which were 0.515 +/- 0.002 and 0.81 +/- 0.014 ng/ml, respectively. The MIC50 of albendazole for E. intestinalis was 8.0 +/- 4.23 ng/ml, significantly less (P < 0.01) than its MIC50 for V. corneae, which was 55.0 +/- 7.07 ng/ml. TNP-470 inhibited replication of E. intestinalis in RK-13 cells if it was given at the same time as infection or if treatment was initiated 7 days later. In addition, treatment of the infected cultures with TNP-470 at a dose of 10 ng/ml for 2 weeks, followed by discontinuation of the drug treatment, resulted in no significant increase in E. intestinalis shedding during the following 3 weeks in culture. Because TNP-470 acts against both E. intestinalis and V. corneae, and because TNP-470 was found by others to be less toxic in vivo, TNP-470 may be a promising new drug for the treatment of microsporidiosis.     

Ethonafide-induced cytotoxicity is mediated by topoisomerase II inhibition in prostate cancer cells

Ethonafide is an anthracene-containing derivative of amonafide that belongs to the azonafide series of anticancer agents. The lack of cross-resistance in multidrug-resistant cancer cell lines and the absence of a quinone and hydroquinone moiety make ethonafide a potentially less cardiotoxic replacement for existing anthracene-containing anticancer agents. For this study, we investigated the anticancer activity and mechanism of ethonafide in human prostate cancer cell lines. Ethonafide was cytotoxic against three human prostate cancer cell lines at nanomolar concentrations. Ethonafide was found to be better tolerated and more effective at inhibiting tumor growth compared with mitoxantrone in a human xenograft tumor regression mouse model. Mechanistically, we found that ethonafide inhibited topoisomerase II activity by stabilizing the enzyme-DNA complex, involving both topoisomerase IIalpha and -beta. In addition, ethonafide induced a potent G(2) cell cycle arrest in the DU 145 human prostate cancer cell line. By creating stable cell lines with decreased expression of topoisomerase IIalpha or -beta, we found that a decrease in topoisomerase IIalpha protein expression renders the cell line resistant to ethonafide. The decrease in sensitivity to ethonafide was associated with a decrease in DNA damage and an increase in DNA repair as measured by the neutral comet assay. These data demonstrate that ethonafide is a topoisomerase II poison and that it is topoisomerase IIalpha-specific in the DU 145 human prostate cancer cell line.     

Status of tracheotomy in treatment of the respiratory emergency in anaplastic thyroid cancer

A review is presented on the 69 patients requiring intraoperative tracheotomy amongst 170 patients with locally infiltrating carcinoma of the thyroid operated on over a 30-year period. 55% of these patients underwent this procedure for absolute indications; in 45% of cases it was performed as a prophylactic procedure to prevent later respiratory complications due to further infiltration by the anaplastic tumour. The follow-up showed that there was no benefit for patients with anaplastic neoplasms from this additional procedure. Most of these patients suffered from local wound healing complications so that obligatory postoperative external radiation could not be administered. The overall prognosis was very poor. Survival was significantly lower still in the group of patients in whom tracheotomy had been performed.     

Lysophosphatidylcholine‐induced cytotoxicity and protection by heparin in mouse brain bEND.3 endothelial cells

A pathological feature in atherosclerosis is the dysfunction and death of vascular endothelial cells (EC). Oxidized low‐density lipoprotein (LDL), known to accumulate in the atherosclerotic arterial walls, impairs endothelium‐dependent relaxation and causes EC apoptosis. A major bioactive ingredient of the oxidized LDL is lysophosphatidylcholine (LPC), which at higher concentrations causes apoptosis and necrosis in various EC. There is hitherto no report on LPC‐induced cytotoxicity in brain EC. In this work, we found that LPC caused cytosolic Ca²⁺ overload, mitochondrial membrane potential decrease, p38 activation, caspase 3 activation and eventually apoptotic death in mouse cerebral bEND.3 EC. In contrast to reported reactive oxygen species (ROS) generation by LPC in other EC, LPC did not trigger ROS formation in bEND.3 cells. Pharmacological inhibition of p38 alleviated LPC‐inflicted cell death. We examined whether heparin could be cytoprotective: although it could not suppress LPC‐triggered Ca²⁺ signal, p38 activation and mitochondrial membrane potential drop, it did suppress LPC‐induced caspase 3 activation and alleviate LPC‐inflicted cytotoxicity. Our data suggest LPC apoptotic death mechanisms in bEND.3 might involve mitochondrial membrane potential decrease and p38 activation. Heparin is protective against LPC cytotoxicity and might intervene steps between mitochondrial membrane potential drop/p38 activation and caspase 3 activation.     

Glycolytic inhibition alters anaplastic thyroid carcinoma tumor metabolism and improves response to conventional chemotherapy and radiation

Anaplastic thyroid carcinoma (ATC) accounts for more than 50% of thyroid cancer mortality and is generally refractory to conventional treatment. On the basis of recent studies, we hypothesized that ATC metabolism can be targeted to improve response to chemoradiotherapy. Eight established and authenticated ATC cell lines were sequenced at 140 sites contained within 26 commonly mutated genes to identify novel potential therapeutic targets. Cellular proliferation, energy, and reducing potential stores were measured under conditions of specific nutrient deprivation. Tumor metabolism was evaluated using hyperpolarized (13)C MRI in a murine orthotopic xenograft model of ATC. Sensitivity to chemotherapeutic agents and radiation (XRT) was assayed using cytotoxicity assays. We identified mutations in BRAF, NRAS, and KIT but failed to identify generalized novel targets for therapeutic intervention. ATC cell lines exhibited a mesenchymal phenotype and generalized dependence on glucose for energy, reducing potential and survival. Glycolytic inhibition using 2-deoxyglucose (2-DG) sensitized ATC cells to conventional chemotherapy and external beam radiation. In vivo, 2-DG induced a transient, but significant reduction in ATC metabolic activity. Generalized dependence of ATC cells on glucose catabolism makes them susceptible to the sensitizing effects of 2-DG for radiation therapy and chemotherapy. Under in vivo conditions, 2-DG can inhibit ATC metabolism. However, the modest magnitude and transient nature of this effect suggest the need for antimetabolic agents with more favorable pharmacodynamics to achieve therapeutic effects.     

Antimicrosporidial activities of fumagillin, TNP-470, ovalicin, and ovalicin derivatives in vitro and in vivo

Therapies for microsporidiosis in humans are limited, and fumagillin, which appears to be the most broadly effective antimicrosporidial drug, is considered to be moderately toxic. The purpose of this study was to apply an in vitro drug screening assay for Encephalitozoon intestinalis and Vittaforma corneae and an in vivo athymic mouse model of V. corneae infection to assess the efficacy of TNP-470 (a semisynthetic analogue of fumagillin), ovalicin, and eight ovalicin derivatives. TNP-470, ovalicin, and three of the ovalicin derivatives inhibited both E. intestinalis and V. corneae replication by more than 70% in vitro. Another three of the ovalicin derivatives inhibited one of the two microsporidian species by more than 70%. None of the treated athymic mice survived the V. corneae infection, but they did survive statistically significantly longer than the untreated controls after daily treatment with fumagillin administered at 5, 10, and 20 mg/kg of body weight subcutaneously (s.c.), TNP-470 administered at 20 mg/kg intraperitoneally (i.p.), or ovalicin administered at 5 mg/kg s.c. Of two ovalicin derivatives that were assessed in vivo, NSC 9665 given at 10 mg/kg i.p. daily also statistically significantly prolonged survival of the mice. No lesions associated with drug toxicity were observed in the kidneys or livers of uninfected mice treated with these drugs at the highest dose of 20 mg/kg daily. These results thus support continued studies to identify more effective fumagillin-related drugs for treating microsporidiosis.     

Tumor necrosis factor-alpha and interleukin-1beta mediate endothelial permeability induced by lipopolysaccharide-stimulated whole blood

OBJECTIVE: To investigate the role of endotoxin-induced inflammatory mediators in blood on the permeability of endothelial monolayers. DESIGN: Whole blood of healthy volunteers was treated with bacterial lipopolysaccharide (Escherichia coli, B55:05), and the resultant plasma was added to human umbilical venular endothelial cells (HUVEC) cultured on semipermeable membrane inserts (Transwells). SETTING: University hospital laboratory. SUBJECTS: Whole blood of healthy volunteers. INTERVENTIONS: Donor plasma was treated with excess antibodies against either tumor necrosis factor-alpha, interleukin-1beta, or both, before the incubation on HUVEC. MEASUREMENTS AND MAIN RESULTS: The permeability of HUVEC monolayers to fluorescent-labeled albumin and dextran was measured over a 6-hr period, after removal of the stimulus. The production of tumor necrosis factor-alpha and interleukin-1beta in lipopolysaccharide-treated whole blood was determined by radioimmunoassay. Individually, lipopolysaccharide (10 microg/mL), tumor necrosis factor-alpha (10 ng/mL), and interleukin-1beta (50 ng/mL) all increased endothelial permeability by about 2.5-fold. A much larger increase could be achieved by preincubation of lipopolysaccharide (10 microg/mL) in whole blood: the resultant plasma induced a ten-fold increase of the permeability. The permeability response after preincubation of lipopolysaccharide in whole blood was time- and dose-dependent. Moreover, this treatment increased the sensitivity of endothelial monolayers to lipopolysaccharide by a factor of several thousand-fold: Whereas high doses of lipopolysaccharide were required for direct stimulation of the permeability, picomolar amounts of lipopolysaccharide in whole blood induced a similar increase. Significant amounts of tumor necrosis factor-alpha and interleukin-1beta were produced in blood at similar doses of lipopolysaccharide. The addition of antibodies against tumor necrosis factor-alpha or interleukin-1beta to plasma partially but significantly abrogated the permeability increase. However, a complete inhibition could be achieved by the simultaneous addition of anti-tumor necrosis factor-alpha and anti-interleukin-1beta to plasma. CONCLUSIONS: Although lipopolysaccharide is capable of directly inducing endothelial permeability, blood-borne tumor necrosis factor-alpha and interleukin-1beta mediate lipopolysaccharide-induced endothelial permeability at low endotoxin concentrations. These findings support the idea that multifactorial inhibition of inflammatory mediators may improve survival in septic patients.     

Rac1 and superoxide are required for the expression of cell adhesion molecules induced by tumor necrosis factor-alpha in endothelial cells

Oxidative signals play an important role in the regulation of endothelial cell adhesion molecule expression. Small GTP-binding protein Rac1 is activated by various proinflammatory substances and regulates superoxide generation in endothelial cells. In the present study, we demonstrate that adenoviral-mediated expression of dominant negative N17Rac1 (Ad.N17Rac1) suppresses tumor necrosis factor-alpha (TNF-alpha)-induced vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), and E-selectin gene expression in a dose-dependent manner. Ad.N17Rac1 did not inhibit TNF-alpha-induced activation of nuclear factor-kappaB (NF-kappaB) binding activity or inhibitor of NF-kappaB-alpha degradation. In contrast, Ad.N17Rac1 inhibited TNF-alpha-induced NF-kappaB-driven HIV(kappaB)(4)-CAT and p288VCAM-Luc promoter activity, suggesting that N17Rac1 inhibits TNF-alpha-induced VCAM-1, E-selectin, and ICAM-1 through suppressing NF-kappaB-mediated transactivation. In addition, expression of superoxide dismutase by adenovirus suppressed TNF-alpha-induced VCAM-1, E-selectin, and ICAM-1 mRNA accumulation. However, adenoviral-mediated expression of catalase only partially inhibited TNF-alpha-induced E-selectin gene expression and had no effect on VCAM-1 and ICAM-1 gene expression. These data suggest that Rac1 and superoxide play crucial roles in the regulation of expression of cell adhesion molecules in endothelial cells.     

Oncogene-specific inhibition in the treatment of advanced pediatric thyroid cancer

Papillary thyroid cancer (PTC) is the most common form of differentiated thyroid cancer in the pediatric population and represents the second most common malignancy in adolescent females. Historically, PTC has been classified on the basis of histology, however, accumulating data indicate that molecular subtyping based on somatic oncogenic alterations along with gene expression profiling can better predict clinical behavior and may provide opportunities to incorporate oncogene-specific inhibitory therapy to improve the response to radioactive iodine (RAI). In this issue of the JCI, Y.A. Lee, H. Lee, and colleagues showed that oncogenic fusions were more commonly associated with invasive disease, increased expression of MAPK signaling pathway genes (ERK score), and decreased expression of the sodium-iodine symporter, which was restored by RET- and NTRK-inhibitory therapy. These findings lend credence to the idea of reclassifying pediatric thyroid cancers using a three-tiered system, rather than the two-tiered adult system, and open avenues for the treatment of progressive, RAI-refractory PTC in patients.     

Reinterventions in anaplastic cancers and sarcomas of the thyroid gland

In the years 1979-1988, operations were performed on 41 anaplastic carcinomas and 11 sarcomas of the thyroid gland. Out of these cases reoperation was indicated in 18 patients (34.6%): in 11 cases only a palliative tracheotomy could be done (group I), whilst in the remaining 7 patients surgical removal of the recurrent tumour was possible (group II). Analysis of group II patients revealed that the initial surgical intervention had been a macroscopically radical operation. The difference between the survival rates of both groups was highly significant (group I 64 days, group II 412 days mean survival). Despite the fatal prognosis of these highly malignant tumours, we conclude that reoperation for the removal of a recurrent tumour is advisable in those patients in whom the initial operation was a radical excision. Longer survival rates and improved quality of life were achieved. If the initial operation was merely palliative, then only a tracheotomy is the likely procedure in case of recurrence.     

Src inhibition enhances paclitaxel cytotoxicity in ovarian cancer cells by caspase-9-independent activation of caspase-3

Src tyrosine kinase has been found to be overexpressed and activated in a high proportion of ovarian cancers and ovarian cancer cell lines. Furthermore, Src activation is associated with activation of growth and survival signaling pathways. The present study was conducted in order to determine the effects of Src inhibition on ovarian cancer cell survival in response to chemotherapeutic agents. Inhibition of Src, either pharmacologically or through expression of a Src dominant-negative fusion construct, enhanced the cytotoxicity of two different classes of chemotherapeutics: paclitaxel and cisplatinum, in both mouse and human ovarian cancer cells. Interestingly, Src inhibition also restored sensitivity to drug-resistant ovarian cancer cells. The increased cytotoxicity in response to Src inhibition was associated with a large increase in processing and activation of caspase-3. The activation of caspase-3 seems to be independent of cytochrome c release and caspase-9 activation. The present study indicates that Src tyrosine kinase may provide an important target for small molecule inhibition in ovarian cancer.     

超声对原发性甲状腺淋巴瘤与甲状腺未分化癌的鉴别诊断

目的 探讨超声对原发性甲状腺淋巴瘤(PTL)与甲状腺未分化癌(ATC)的鉴别诊断.方法 回顾性分析2004年9月至2019年11月四川大学华西医院73例PTL和28例ATC患者的临床、病理和超声表现.年龄、病灶最大径及杨氏模量值最大值(Emax)、杨氏模量值最小值(Emin)、杨氏模量值平均值(Emean)、甲状腺病灶...     

烟酸抑制血管紧张素Ⅱ诱导的内皮细胞凋亡

目的探讨烟酸对血管紧张素Ⅱ诱导的人脐静脉内皮细胞(HUVECs)凋亡的影响。方法分别使用不同浓度烟酸(0.25 mM,0.5 mM或1.0 mM)预处理HUVECs不同时间(1 h、3 h、6 h、12 h)后,使用血管紧张素Ⅱ(1μM)诱导HUVECs凋亡。终端转移酶介导的dUTP缺口标记技术(TUNEL法)检测内皮细胞的凋亡指数;H2DCF-DA荧光标记法测定细胞内氧自由基(ROS)的生成。结果预处理一定时间后,烟酸能抑制血管紧张素II诱导的HUVECs的凋亡,而且这种抑制呈浓度依赖性。HUVECs在使用1 mM烟酸预处理6 h后,血管紧张素II加烟酸(AngII+Niacin)组与血管紧张素Ⅱ(AngII)组相比,ROS的生成有明显降低(P<0.05)。结论烟酸能抑制AngII诱导的HUVECs凋亡,抑制ROS生成是可能的机制之一。     

CD133在未分化甲状腺癌肿瘤干细胞中的作用研究

目的探讨CD133与未分化甲状腺癌肿瘤干细胞的联系,为新的治疗方向提供研究基础。方法利用流式细胞技术分析未分化甲状腺癌ARO细胞株中的CD133阳性百分比,采用磁珠分离技术分离CD133阳性及CD133阴性亚群细胞,分别用RT-PCR技术检测OCT-4基因表达,并观察其肿瘤细胞球的形成。结果 CD133阳性细胞在未分化甲状腺癌ARO细胞株中占8.9%,CD133阳性细胞的OCT-4蛋白表达明显高于CD133阴性细胞(P<0.05),且更容易形成肿瘤细胞球,提示CD133阳性细胞的体外增殖能力比CD133阴性细胞强,具有肿瘤干细胞的特性。结论 CD133阳性可能是未分化甲状腺癌的肿瘤干细胞标记物之一。     

Combretastatin A4-induced differential cytotoxicity and reduced metastatic ability by inhibition of AKT function in human gastric cancer cells

Combretastatin A4 (CA4) is a drug that targets tumor vasculature to inhibit angiogenesis. Whether CA4 has a direct effect on gastric cancer is not known. We herein investigated the effect of CA4 on growth and metastasis of gastric cancer cells at clinically achievable concentration and explored the associated antitumor mechanisms. Nine human gastric cancer cell lines, including two metastatic gastric cancer cell lines (AGS-GFPM1/2), constitutively expressing green fluorescence protein (GFP) were used. These metastatic AGS-GFPM1/2 cells expressed a higher level of phosphorylated serine 473 on AKT (p-AKT). Our results showed that CA4 (0.02-20 microM) has significant in vitro effects on reducing cell attachment, migration, invasiveness, as well as cell cycle G2/M disturbance on p-AKT-positive gastric cancer cells. In addition, a phosphoinositide 3-kinase inhibitor, LY294002 [2-(4-morpholinyl)-8-phenyl-1(4H)-benzopyran-4-one hydrochloride], a specific AKT inhibitor, and 0.2 to 20 microM CA4 displayed a similar response profile on p-AKT-positive cells, suggesting that CA4-induced effect was mediated by inhibition of the PI3 kinase/AKT pathway. The results from in vivo GFP monitoring system indicated that CA4 phosphate (CA4-P; 200 mg/kg) significantly inhibited the s.c. and intra-abdominal growth of xenotransplanted AGS-GFPM2 cells in nude mice. Furthermore, CA4-P treatment showed a remarkable ability to inhibit gastric tumor metastasis as well as attenuate p-AKT expression. In conclusion, our study is the first to find that CA4 inhibited AKT activity in human gastric cancer cells. The decreased AKT activity correlated well with the CA4 antitumor growth response and decrease of metastasis. Further investigation on drugs targeting the PI3 kinase-AKT pathway may provide a new approach for the treatment of human gastric cancer.     

Results of combined modality treatment in poorly differentiated and anaplastic thyroid carcinoma

From 1973-1989 34 patients with poorly differentiated primarily inoperable and 89 with anaplastic giant-cell thyroid tumours entered a study on individualized multimodal treatment. The aim of the study was to find an effective, non-aggressive chemotherapy (ChT) and explore the possibility of individualized combined treatment. Infusions of low doses of vinblastine or cisplatinum or adriamycin or novantrone were used for perturbation of cellular kinetics in the tumours. Sequential fine-needle aspiration biopsies of tumours were performed for monitoring the drug-induced changes in tumour cells and for cytomorphological studies and DNA measurements, on the basis of which ChT was individualized. During the period of accumulation of cells in the S or G2 + M phases, drugs particularly effective in the respective phases were used. The same principle was used in planning a combination of ChT and irradiation. In the group of poorly differentiated carcinomas only 5/34 patients had MR to ChT. In 17/34 patients after ChT the tumour was removed surgically, 19/34 have NED 11+ to 72+ months after treatment. The results in 89 patients with anaplastic carcinoma are worse: 13/89 patients died before or at the beginning of treatment, of 77 treated patients only 10 could be operated on, 7 survived for more than one year (13+ to 72+ months). Only 1/77 patients survived for more than 5 years. A combination of DNA measurements and cytomorphological studies is a useful method for the understanding of tumour behaviour under treatment.     

促红细胞生成素预防人脐静脉内皮细胞凋亡的作用

目的 建立氧化低密度脂蛋白(ox-LDL)诱导培养人脐静脉内皮细胞(HUVECs)凋亡模型,探讨促红细胞生成素(EPO)对ox-LDL诱导HUVECs凋亡的影响.方法 取体外培养3～6代的HUVECs用于实验.实验分为两组:一组细胞予以不同浓度(6.25、50、100 kU/L)重组人促红细胞生成素(rhEPO)预处理24 h,再加入100 mg/L ox-LDL孵育48 h;另一组细胞加入反式或顺式LOX-1 mRNA预处理24 h,再加入 100 mg/L 的ox-LDL孵育12 h.采用存活率、凋亡率和Bcl-2/Bax比值评价细胞凋亡情况.结果 与ox-LDL组比较,随rhEPO浓度的递增,细胞存活率增高,细胞凋亡率降低,凋亡蛋白Bcl-2/Bax比值增高(P均<0.05),呈剂量依赖性.反式LOX-1 mRNA(0.5 μmol/L)预处理组凋亡蛋白Bcl-2/Bax比值较ox-LDL组明显增高(P<0.05);顺式LOX-1 mRNA(0.5 μmol/L)预处理组Bcl-2/Bax比值与ox-LDL组则无明显差异.结论 ox-LDL可以诱导HUVECs凋亡,并且通过LOX-1 mRNA来调节,rhEPO可增高Bcl-2/Bax比值,抑制ox-LDL诱导的HUVECs凋亡.     

Tumor growth inhibition in vivo and G2/M cell cycle arrest induced by antisense oligodeoxynucleotide targeting thymidylate synthase.

Chemotherapeutic agents targeting thymidylate synthase (TS) are effective against human tumors. Efficacy is limited by drug resistance, often mediated by TS overexpression. Treatment of HeLa cells in vitro with an antisense oligodeoxynucleotide (ODN 83) targeting human TS mRNA reduces TS mRNA and protein levels, inhibits cell proliferation, and sensitizes cells to TS-targeting drugs (Ferguson et al., 1999). The present study investigates the mechanism by which ODN 83 inhibits cell proliferation and examines its antitumor efficacy in vivo. ODN 83 treatment did not induce apoptosis in HeLa cells in vitro but caused accumulation of cells at G2/M. In contrast, TS-targeting chemotherapeutics arrest at G1 or S. Antisense down-regulation reduced TS mRNA levels in human colon cancer (HT29) cells by 40% in vitro, resulted in G2/M arrest, and reduced proliferation without enhanced cell death. Growth of HT29 tumors in immunocompromised mice was significantly inhibited when antisense ODN 83 treatment began promptly after tumor implantation and was accompanied by a 40% reduction in TS protein levels. Growth of tumors allowed to reach 400 mm3 prior to ODN administration was unaffected by antisense ODN 83. Radiolabeled ODNs were localized to the tumor periphery but evenly distributed in normal tissue. Thus, down-regulation of TS mRNA and protein by antisense ODN treatment exerts a novel G2/M cell cycle block without increasing cell death and inhibits HT29 tumor cell growth in vivo. Antisense ODN 83 may be an effective therapy for colon carcinoma, alone or in combination with TS-targeting cytotoxic drugs.